package io.renren.common.sms;

import java.util.Random;

/**
 * 验证码
 * 
 * @author ypj
 *
 */
public class CheckCodeUtils {

	/**
	 * 取得6位随机不同的数
	 */
	public static int random() {
		int[] array = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
		Random rand = new Random();
		for (int i = 10; i > 1; i--) {
			int index = rand.nextInt(i);
			int tmp = array[index];
			array[index] = array[i - 1];
			array[i - 1] = tmp;
		}
		int result = 0;
		for (int i = 0; i < 6; i++) {
			result = result * 10 + array[i];
		}
		return result;
	}

	/**
	 * 返回长度为size,随机从A~Z,0~9中选取 的字符组成的字符串
	 */
	public static String getCode(int size) {
		String code = "";
		String strs = "ABCDEFGHIJKLMNOPQRST" + "UVWXYZ0123456789";
		Random r = new Random();
		for (int i = 0; i < size; i++) {
			code += strs.charAt(r.nextInt(strs.length()));
		}
		return code;
	}

}
